Rus Horse Archer should have 2.125s (~2.12s) Attack Speed with the new update.
However, after researching Incendiary Arrows, their Attack Speed reverts to the 2.625s (~2.62s) Attack Speed from before the patch.
Additionally, when not bugged with the Incendiary Arrow upgrade, the new Tooltip says 2.12s Attack Speed, but the actual attack speed is 2.25s experimentally. Hopefully, this gets fixed as well.
Build: 5.0.17718.0